Automatic sampler of liquid and gas phase streams



Dec. 19, 1950 L. A. WEBBER ETAL AUTOMATIC SAMPLER OF LIQUID AND GASPHASE STREAMS Filed July 2, 1945 3 Sheets-Sheet 1 S W WM R O INVENTORSL..A.WEBBER O.W.KIPHART ATI' Dec. 19, 1950 L. A. WEBBER ETAL AUTOMATICSAMPLER OF LIQUID AND GAS PHASE STREAMS s Sheets Sh eet 2 Filed July 2,1945 INVENTORS L ANVEBBE R QWNPHART ATTORN 5 Dec. 19, 1950 A. WEBBERETAL AUTOMATIC SAMPLER 0F LIQUID AND GAS PHASE STREAMS 3 Sheets-Sheet 3Filed July 2, 1945 INVENTORS L AWEBBER ATTORNE Patented Dec. 19, 1950AUTOMATIC SAMPLER OF LIQUID AND GAS PHASE STREAMS Ludwig A. Webber andOtta W. Kiphart, Borger, Ten, asslgnors to Phillips Petroleum Company, acorporation Delaware Application July 2, 1945, Serial N 0. 602,818

7 Claims.

This invention relates to sampling devices. In one of its more specificaspects, it relates to devices and methods for sampling of fluids. Thedesign and construction of automatically operated equipment for samplingof fluids has yielded heretofore relatively costly and usually rathercumbersome and awkwardly operating equipment. We have found that theprinciple involved according to our invention may be applied to samplingdevices for use in the composite sampling of either gaseous or liquidstreams. Our. invention has special application in the petroleumindustry but may be used as well in chemical or other industries whereliquids or gases are to be sampled, compositely, over periods of time.

One object of our invention is to provide apparatus and a method forsampling of streams of fluids while in transit.

Another'object of our invention is to provide a method and apparatuswhich may be used for the taking of composite samples of either liquidsor gases over rather long periods of time.

Still another object of our invention is to provide an apparatus for thecomposite sampling of gas streams at pressures less than atmospheric.

Still another object of our invention is to provide an apparatus for thecomposite sampling of gas streams at pressures greater than atmosphericpressures.

These and other objects and advantages will beapparent to those skilledin the art upon reference to the following detailed description andannexed drawing which respectively describes and illustrates preferredembodiments of our invention, and wherein Figure 1 illustrates anembodiment of our invention adapted for the sampling of hydrocarbonliquids which vaporize upon release of pressure.

Figure 2 illustrates an embodiment of our invention adapted for samplingstreams of noncondensible gases or normally liquid streams underpressures greater than atmospheric.

Figure 3 illustrates an embodiment of our invention adapted for samplingstreams of gases or liquids at pressures less than atmospheric pressure,

Referring to the drawing and specifically to Figure 1 numerals ll, l2and I3 refer to motor air pressure. The flexible diaphragms H; areattached in conventional manner to valve stems l I and by movement ofthe diaphragm members the valve stems and accordingly the needle closureportions l4 are opened or closed. These valves may be spring loaded, asby springs :5. As shown in the drawing, each spring l8 serves as atension spring and is so adjusted as to hold the valve needle in anormally closed position. Upon application of instrument air pressure tothe under side of the diaphragms, the valve stems H are raised to openthe valves to the flow of fluid, the springs l8 being accordinglysubjected" to somewhat greater tensions. When the instrument airpressure is released, the normal tension of the springs moves the valveneedles into their normally closed position.

A proportioning chamber I9 is inserted to connect motor valves H, I! andI 3 as illustrated in Figure 1. This proportioning chamber may be astandard pipe or copper tube T-fitting provided its inside or passagewayvolume is the volume required for the taking of predetermined sizesamples. Connections H which connect this proportioning chamber to therespective motor valves H and I2 should be as short as possible and ofas small a bore as is practical with the desired sturdiness ofconstruction. A tube 24 is attached to the outlet end of motor valve 12to direct disposal of material not desired as sample.

A tube 22 connects the side arm outlet of the proportioning member IE tothe motor valve l3. From the delivery side of this latter valve is asample tube 23 for conducting the sample from the sample takingapparatus to a sample container, not shown.

Atiming apparatus 25 such as a time cycle controller is shown as a meansfor controlling the several motor valves according to predetermined timeintervals. While this time cycle controller may be any type orkind ofcontroller desired, it is obviously only necessary that it be capable ofperforming the desired operations in a satisfactory manner. By this, wemean that the controller may be electrically operated or it may beoperated by a spring operated clock mechanism. A particular time cyclecontroller which we have used and found to be entirely satisfactory isone.

manufactured by the Hanlon Waters Company, and is mentioned hereinmerely as an example. The time cycle controller which we have usedoperates on a six hour cycle, but by repeating the six'hour cycle asmany times as desired a composite sample of any desired size or over anydesired period of time may be taken.

Time cycle controllers, such as the one mentioned above, operateaccording to pins, placed in holes around the circumference of arotating plate. Thus by inserting pins into these holes over certaintime intervals said pins, upon rotation of the plate, cooperate withother mechanism of the controller to permit flow of instrument air tosuch control apparatus'as the air operated motor valves l2 and I3. Suchtime cycle controllers as the one hereinabove mentioned are standardindustrial equipment and may be purchased from equipment dealers ordirectly from instrument manufacturers.

Instrument air from an air supply, not shown, comes by way of a line 21and passes through an air pressure reducer or regulator 26 to reduce theair pressure to that required for operation of such motor valves. Thisregulator 26 also contains a strainer element for elimination of foreignmaterial from the air previous to entrance into the cycle controller.Said cycle controller contains valves for transmitting air pressure fromthe inlet air line 21 to air control lines 28 and 29 and for closing Hand exhausting air pressure from said line 28 and 29.

Since motor valves II and I2 are intended to operate simultaneously,they are operated off the same air line 29 by running branch air lines3| and 32 to said motor valves. Line 28 admits air only to motor valvel3. As shown in Figure 1,

these several air service lines transmit air pressure to the under sideof the motor valve diaphragm members l6 so that an increase ofinstrument air pressure on the underside of said diaphragms will operateto raise the diaphragms and piped to the upper side of the diaphragmsand.

operate to close the valves by compression of the springs I8.

In the operation of the modification of our invention shown in Figure 1for th sampling of a liquid hydrocarbon, such as butane, which willcompletely vaporize at atmospheric pressure, the liquid hydrocarboncomes from its transfer line through a small diameter sample line andenters motor valve H. For taking a sample of butane the time cyclecontroller clock operates to admit instrument air from air line 21 toair line 29 and thence into the two branch air lines 3| and 32. Fromthese branch lines the air pressure is transmitted to the diaphragms ofvalve motors (I I. and I2) which motors respond by opening theirrespective valves. Liquid butane then flows from line 20 through motorvalve ll, tubes 2| and the proportioning chamber I9, mofor valve l2 andthrough bleed ofl. line 24 to such disposal as desired. The controlclock holds these valves open for such a predetermined time as isthought necessary to flush out thoroughly any residual material, ofcourse motor valve I2 remaining closed. When such flushing is complete,the cycle clock operates to permit closing of the valves H and i2 andaccordingly there is re-.

tained in the proportioning chamber and connecting elements a measuredvolume of liquid butane.

Finally, the cycle controller admits air pressure by way of tube 22 tothe motor valv II to open said valve. The liquid butane in theproportioning chamber then vaporizes and t e p s 1 obtained t e volumeor chamber II by difference.

.4 pass through the valve l3 and are led to a sample collecting device32. We have found that the sample vapors may be collected bydisplacement of brine from a container 34, as say, a 5-gallon bottle.Other liquids may be used for displacement purposes but we prefer to usea salt water brine since hydrocarbon gases are relatively insoluble insuch a solution. In case a larger sample than 5 gallons is desired itis, of course, only necessary to use a larger bottle, and vice versa ifa smaller sample is desired.

Several conditions of apparatus and operation may be varied for takingvarious sizes of samples, etc. For example, for taking a 24-hourcomposite sample of butane, the concentration of which does not varyappreciably, a sample each hour over said period might be suilicient.However, in case the composition of a stream being sampled variesconsiderably from time to time, it might be necessary to take compositesamples each 15 minutes or each half hour in order to obtain a trueaverage of a 24-hour run. To vary the periods of sampling it is onlynecessary to insert pins in the rotating disc of the time cyclecontroller at the proper time points, that is, for 15 minute, 30 minuteor 1 hour operation. We have used a 6-hour time cycle controller fortaking samples of butane each 15 minutes over a 24 hour period, therebymaking the 24-hour sample a composite of 96 individual samples. The pinsin the rotating disc are so inserted as to permit valves II and I2 toremain open for about one minute, during which time the previous sampleis well flushed from line 20, valves II and I2 and the connecting parts.Valves II and I2 then close and valve It opens and remains open forabout 5 minutes which time has been found ample for completevaporization of the sample from the proportioning chamber l9 andtransfer of the vaporized sample into the sample collecting bottle 34.At the end of such period valve i3 closes and the sampling apparatusthen awaits th next sampling time as determined by the time cyclecontroller 25.

One of the critical points in our apparatus 01' Figure 1 is the volumeof the proportioning chamher It and connecting parts. In case the volumeor this chamber I! were too large, then a 5-gallon sample bottle mightbecome filled with butane vapors with two or three samples instead of 24hourly samples over a 1-day operating period. The eilective volume to beconsidered from this point of view is the total volume of thepropertioning chamber portion of the apparatus and this includes thevolumes of all members from the needle I4 in motor valve tube 2|,chamber I9, tube 2| (extended), to the needle I 4 in motor valve l2, andtube 22 to the needle H in motor valve l3. Thus, twenty-four times thistotal volume of liquid when vaporized will be the volume or the gassample collected. In order to collect a composite gas sample ofreasonable size, say five'or ten gallons. this total volume must berelatively small as will be obvious to a chemist. For this reason, weprefer to use small bore tubing for tubes 2| and 22 and these tubesshould be as short as practical. In addition, the diameter oi thehydrocarbon conduit through said motor valves must be relatively small.In making our apparatus of Figure 1, we determined by calculation thetotal liquid butane volume re- 4 quired for this proportioning chamberportion" or the apparatus, and knowing the volumes or the 7 motor valveconduits, tubes 2| and 22, then we asscaao This procedure will need tobe followed for making our apparatus for sampling such hydrocarbons asbutane, isobutane, the butenes. etc. taking into consideration thevolume of composite sample to be taken, the total time period over whichthe sample is to be taken, and the frequency for taking the individualsample fractions.

" We have found that once an apparatus of this character is properlyconstructed that it requires no man power for operation and all the timeneeded is that required for changing sample bottles.

The apparatus may well be housed within a box or other container forprotection. However, the brine tank and sample bottle need not becompletely housed but may be arranged under a roof to aflord protectionagainst such elements as rain, hail, snow, etc.

The embodiment of our invention illustrated in Figure 2 of the drawingis adapted to sampling of noncondensible gases under pressure. Theprinciples and main points of operation are similar to those abovedescribed in relation 'to use of 1 apparatus of Figure .1. In the deviceof Figure 2. gas under pressure and to be sampled comes from a vessel tobe sampled by way of a line 4|,passes through a motor valve 42, andthrough a connecting tube 43 into a proportioning chamber 44. From thisreservoir or proportioni'ng. chamber 44 the sample of gas passes througha connecting tube 45, a second motor valve 46, through a transfer tube41 and thence into a sample bottle 48. As sample gas passes into thesample bottle, liquid which for our purpose may be a brine solution, isdisplaced and flows into a brine tank 50, the level "or the brinesolution being indicated by reference numeral 49. Instrument air from asource, not shown, comes through an air line 52,

sure gages 54, 56 and 59 indicate the instrument air pressures in theserespective control lines. The motor valves 42 and 46 may well be of thesame type as those described in relation to Figure 1 and contain valveneedles 63 and 64, and tension springs 65 and 66.

In the operation of this embodiment of our invention, the time cyclecontroller is set to operate at quarter hour, half hour, or hourintervals as desired. Instrument air from line 52 passes through thecycle controller 55, air line 56 to the under side of diaphragm 60. Airpressure at this point opens the valve needle 63 against the tension ofspring 65. Under these conditions gas to be sampled under pressure flowsfrom line 4| into the proportioning chamber 44, of'course, motor valve46 remaining closed.

Valve 42 remains open for a sutlicient period of time to permit pressurein the proportioning chamber 44 to become equal to that in sample line4i. This period of time, however, is relatively short since the volumeof the proportioning chamber is rather small. The valve, however, isusually set to remain open the minimum length of time obtainable on thespecific cycle controller used. When the proportioning chamber is fullypressured, then valve 42 closes, and valve 46 then opens and permitsexpansion and flow of the exthe mercury reservoir 83.

panded gas through the valve and sample tube v in this condition untiltime for taking another sample.

The critical point in this particular gas sampling apparatus (of Figure2) is the size of the proportioning chamber 44. The size or volume ofthis chamber should be such that for sampling a gaseous material under acertain pressure, that the required number of time spaced-individualsamples will not yield a composite sample of volume greater than thevolume of the sample bot tle 48. It will be obvious that the greater thepressure of the gas bein sampled, and the greater the number of samplestaken over a period of time, the smaller the sample chamber may be. Forutility of sampling apparatus, we have found it advisable to makeprovision for the proportioning chamber to be removable from theapparatus so that various size chambers may be inserted depending uponsample requirements.

The apparatus shown, diagrammatically, in Figure 3 is intended forsampling gas streams or normally liquid hydrocarbons at slight vacuum orat a pressure too low to displace brine from a sample bottle. Thisapparatus is similar in many respects to those of Figures 1 and 2, butdiffers mainly in that a Toepler pump is used as a means for transfer ofthe gas from the process line under slight vacuum to a sample bottleunder atmospheric pressure.

Referring to the Figure 3, instrument air from an air line lfl'passesthrough a time cycle controller mechanism TI and thence through lines 12'and'iil. This time cycle controller may be similar to those describedhereinbefore or any other type desired, provided it is suitable for thepurpose at hand. Four motor valves, 15, 16, I1 and 16, are also similarto those mentioned in relation to Figures 1 and 2. A Toepler typemercury pump 82 is used as the actual means for transferring the sampleof gas from the process line, not shown, through sample tubes 89 and 90into a gas sample bottle 9|. This pump consists essentially of a mercuryreservoir 83, a sample tube 84 and a mercury transfer tube 94. The topof the sample tube portion of the pump has an outlet for connection to atube 86; the mercury reservoir is provided with an opening forconnection to a pipe 85.

In the operation of this embodiment of our invention (Figure 3), thetime cycle controller operates to admit instrument air from pipe 10 totube 19 and thence to tube and the diaphragm of. motor valve 16, and totube 8! and the diaphragm of motor valve 18. These two motor valves thenare forced open against the tension of their respective tension springs.With valve 16 open, air from another source under about 10 pounds persquare inch gage pressure enters through air line 81, passes through thevalve 16, pipe and into the upper portion of This air pressure forcesthe mercury from the reservoir 83 through tube 94 into the sample tube84 to displace a sample of gas previously taken, forcing it through tube86, motor valve 18 and sample tube 90 into the sample bottle 9| therebydisplacing an equivalent quantity of the brine solution.

The height to which the mercury rises in the 3 sample tube 84 may becontrolled by the pressure of the air entering through tube 88 or by a1float valve mechanism so arranged as to pre- .vent the mercury fromrising from the sample 1 tube 84 into the sample outlet tube 95.

;: -After the mercury has completely expelled all sample gas from I tube84, the air pressure is r maintained on themeroury in vessel 83 untilthe time cycle controller operates to close motor 1 v valves:'|8 and I8.Following the closing of these two valves the cycle controller thenoperates to open valves 15 and 11. The opening of valve 15 releases theair pressure from the mercury reservoir by way of air lines 85 and 88,while the opening of valve 'I'l opens up the sample line to thehydrocarbon or other gas being sampled. Accordingly the release of airpressure from the reservoir 83 permits the mercury to flow from samplechamber 84 to the vessel 83 while at the same time sample chamber 84 isbeing filled with sample gas from tubes 86 and 88. After. passage ofsuflicient time for the sample tube 90 to displace a small volume ofbrine from the sample container 9|. operation completes an individualcycle.

Time cycle controllers such as the Hanlon Waters time cycle controllers,which we have This last sampling used and which we mention by Way ofexample,

are standard equipment and may be purchased from instrumentmanufacturers or dealers. Many different kinds and types of suchequipment are on the market and. a user may use his judgment inselecting the one most suitable for the problem at hand.

The cycle controller to be used in conjunction with our samplingapparatus should be easily adjustable for the particular samplingconditions and should permit some of the operational steps to take placerapidly to prevent air leakage, or loss of or contamination of sample,while other operational steps should be of relatively long duration.These latter steps are necessary to permit passage oil sufficient timein order to be able to take samples at such intervals as to 1 hour. Inaddition, in case it is desired to take samples at short intervals, sayfrom 5 to minutes, the controllers should be so adaptable. As mentionedhereinbefore, an operator may select from among many controllers sincethere are rather large numbers on the market.

When using the embodiment of Figure 3 for sampling normally. liquidhydrocarbons, it is usually not necessary to take as large a sample asfive gallons even over a 24-hour period and accordingly a smaller samplebottle may be used. The sample chamber 84 for this service will then bemade of size as to give a. desired volume of composite sample over adesired period of time.

In like manner, the motor valves for use in our sampling apparatus maybe selected from among many types of motor valves listed inmanufacturers catalogues. Among the many kinds or types of valvesavailable we have found that needle valves are quite satisfactory.However, we do not wish to limit our invention in any way to the use ofneedle valves since other valves are satisfactory as, for example, plugtype valves. We have found, however, that when using needle valves inconjunction with fluid operated diaphragm motors that we can construct asampling apparatus for a very reasonable cost as compared to costs whenusing other valves with the necessary operating and control equipment.

In relation to the embodiment of our invention illustrated by Figure 1wherein a liquid sample is withdrawn, allowed to vaporize, then passedto a-sample container as a gas. the volume of liquid involved is ofimportance. If, for example, a fivegallon sampleof butane vapor isdesired as a composite sample to be representative of a 24- hour periodof operation, and the five-gallon sample is to be made up of 48individual samples taken at minute intervals, it is obvious that each ofthe 48 individual samples must be relativel small. By calculation, basedon a liquid density of butane as 0.6, then 5 cubic inches of liquidbutane will vaporize to give iive gallons of butane vapor at 32 F. and 1atmosphere pressure. Each half hour sample should be approximately 0.1cubic inch of liquid butane. Based on this reasoning, it is obvious thatthe volume of one individual sample of butane taken by the apparatus(Figure 1) will be the volume between the seats of motor valves ll, l2and I3, which volume includes one-half the fluid passageway in each ofthese valves, tubes 2| and 22, and proportioning chamber-l8. Thus thesummation 01 these several volumes should be approximately 0.1 cubicinch in order that 48 individual samples will give about 5 gallonsvapor. In making up an apparatus of this embodiment, it is thennecessary to use motor valves having very small diameter fluidpassageways, connecting tubes 2| and 22 should also be small diametercopper tubing, for example, while the total volume may be adjusted byselection of a proper volume of the proportioning chamber l8. Such smalldiameter materials, as tubing and the like, are readily available, whilesmall size motor valves might need have their fluid passageway diametermade smaller. In one instance,we have filled the passageways in 4 inchmotor valves with lead then'drilled out a small diameter passageway onthe liquid sample side of the needle.

For the embodiments of our invention illustrated by Figures 2 and 3, nospecial small volume apparatus is required since gases are being sampledand the samples retained as gas in each case.

The individual parts of each of the three samplers are relatively small,and we have found that each sampler can be assembled on a wooden ormetal base approximately 2 feet square and the base setinto a housinghaving a side hinged door. The brine tank and sample bottle may best bedisposed outside and adjacent the apparatus box.

In the embodiment of Figure 3 for sampling gases at less thanatmospheric pressure, care must be taken that the mercury from vessel 83is not forced over the top of sample vessel 84. As mentionedhereinbefore, this point may be controlled by maintaining a certainmaximum air pressure on the air in air line 81, and for each maximumpressure there will be a certain and fixed height to which the mercurywill be forced as measured by the difference in mercury levels invessels 83 and 84. For example, 15 pounds will call for the X distancein Figure 3 to be about 30.6 inches, while 10 pound air will decreasethis from air inlet pipe 81 can be depended upon not to exceed certainpressures, a check valve will not be needed in the outlet tube 95. Wewould. however, recommend installation of such a valve in allinstallations as a matter of safety to assist in preventing loss ofmercury.

In all cases, the volume of mercury in the reservoir 83 must cover theopen outlet end of the tube 94 to prevent passage 01" air into thesample tube 84 with subsequent contamination of sample in the bottle 9|.

Also, as mentioned hereinbefore, the sampling intervals, etc. may bechanged at will merely by changing adjustments in the time cyclecontroller, and such adjustments" are well understood by those whooperate such equipment.

Materials of construction may be selected from among those commerciallyavailable and suitable for the particular purpose at hand. Ifnon-corrosive and chemically inactive gases are being sampled, ordinarymaterials may be used. If, however, sampling of corrosive gases is to bedone, materials of construction should be resistant to such corrosion. v

In relation to the motor valves, we have found that the metal typediaphragms work well in these small valve motors. If other kinds ofdiaphragms are found suitable, they may be used in place of those whichwe mention. Even stopcock type valves may be used, but since theserequire electric motors for opening and closing, and complicated relaysand wiring, we have found our air-operated samplers as herein disclosedare by far the least expensive to construct, and are simple andefllcient to operate and are essentiallv fool-proof, that is, they haveoperated for long periods of time without exhibiting mechanicaldifliculties or troubles. It will be obvious to those skilled in the artthat many alterations and. modifications of our samplers may be made andyet remain within the intended spirit and scope of our invention.

What we claim is: i

1. A fluid sampling system comprising in combination at least two valvesconnected by a pro:- portioning chamber and providing fluid flowtherethrough; a fluid sample inlet conduit connected to the open end ofone of said valves; a gas sample collector vessel; a gas sample outletconduit extending from the tree end or one of said valves to said gassample collector vessel; fluid actuated valve operating means in each.said valve; conduit means extending between a source ofpressurized-fluid and said valve operating means; and a controller insaid conduit means, adapted to control the flow or saidpressurized-fluid to said valve actuating means so as to alternatelyactuate said valve in the inlet to said proportioning chamber and saidvalve in the outlet end or said chamber.

2. The fluid sampling system of claim 1, wherein a third valve isconnected to said proportioning chamber; agas vent conduit is connectedto the tree end or said valve; and pressurized- 10 fluid conduitsconnect the actuating means or said third valve and said valve in theinlet to said proportioning chamber to the same source ofpressurized-fluid from said controller.

3. The fluid sampling system of claim 1, wherein one pressurized-fluidconduit extends between said controller and said actuating means of thevalve in the inlet of said proportioning chamber; and a secondpressurized-fluid conduit extends between said controller and said valveactuating means in the valve in the outlet of said proportioningchamber.

4. The fluid sampling system of claim 3, wherein a pressurized-fluidactuated gas pump is provided in said proportioning chamber; and a thirdpressurized-fluid conduit extends between said pump and the same sourceof pressurized-fluid from said controller as said secondpressurizedfluid conduit.

5. A fluid sampling system for sampling gas at atmospheric to slightlybelow atmospheric pressure comprising in combination a proportioningchamber having an inlet and an outlet; a first motor valve in said inletof said proportioning chamber; a second motor valve in said outlet ofsaid proportioning chamber; a

gas sample collector vessel; a first fluid conduit connecting saidsecond motor valve and said gas sample collector vessel; a mercurydisplacement fluid pump connected to said proportioning chamber; apressurizing system for said fluid pump comprising a pressurized-fluidconduit connecting a pressurized-fluid source and said fluid pump, andat least one motor valve in said pressurized-fluid line; and means foroperating said motor valves.

6. The fluid sampling system of claim 5, where-v in a time cyclecontroller is in operational com munication with said means foroperating said motor valves.

'7. The fluid sampling system of claim 5, wherein a second fluid conduitconnects a constant pressure compressed air source and an air flow timecycle controller; and said air flow controller is connected to saidmotor valves by additional fluid conduits.

. LUDWIG A. WEBBER.

O'I'I'A W. KIPHART.

REFERENCES cr'ran The following references are 01' record in the file ofthis patent:

UNITED STATES PATENTS McPherson and Henderson publication entitledCourse in General Chemistry, 2nd ed.; published by Ginn 8: Cg, Boston,Mass., pp. 44 to 46.

